This application is for renewed support for the Training Program in Microbiology for Infectious Diseases, first funded in 1977. We seek to provide trainees with the experimental breadth and biological perspective to produce a new generation of dynamic contributors to research in Microbiology and Infectious Diseases. The 21 members of our Program Faculty have research programs that focus on Immunology (Calame, Clynes, Gu, Reizis, Rothman, Schindler, Zou), Pathogen Biology (Figurski, Goff, Luban, Mitchell, Racaniello, Shuman, Silverstein, Young), and Model Systems (Carlson, Chang, Gottesman, Rothstein, Symington, Waldburger) that pertain to understanding both pathogen and host. Our lecture and seminar courses provide training in basic biological principles and in Immunology, Virology, and Microbial Pathogenesis. Students from several biomedical science graduate programs enter labs of our Program Faculty, and we will choose trainees for support based on their commitment to Microbiology and our evaluation of their academic performance. Thus we will be able to choose the students whose interests parallel our training objectives and whose academic and research accomplishments predict continued success. Among 27 predoctoral trainees who received a Ph.D. in Microbiology in the reporting period, 2 are Assistant Professors, 1 is an Instructor, 14 are postdocs, 2 are science writers, and 8 have gone on to other careers. Among 8 supported postdoctoral trainees, 3 are now tenure-track Assistant Professors. Our program remains dynamic. It has been modified in response to scientific advances, to our refined understanding of the needs of trainees, to changes in graduate program structure at Columbia, and to the scientific evolution of our faculty. Yet the goals enunciated in our original application over 25 years ago remain our goals today: (1) to provide a broad and sound education in the molecular biology and genetics of infectious disease and host responses, and (2) to provide rigorous research training in an environment dedicated to advancing biomedical science. [unreadable] [unreadable]